The example of disk galaxy rotation curves is given for inferring dark matter from redundant computational procedure because proper care of astrophysical and computational context was not taken. At least three attempts that take the context into account have not found adequate voice because of haste in wrongly concluding existence of dark matter on the part of even experts. This firmly entrenched view, prevalent for about 3/4ths of a century, has now become difficult to correct. The right context must be borne in mind at every step to avoid such a situation. Perhaps other examples exist. Keywords: dark matter; disk galaxy; rotation curve; context-awareness. Topics: Algorithms; Applications.